The Lights & Sounds of Tinseltown

Key Stage 2

INTRODUCTION

The Lights and Sounds of Tinseltown is based on the sections on light of the National Curriculum for Science. We aim to make the scientific content self-explanatory but these notes will give you a guide to the topics covered so that preparatory and follow-up work can be done.

Our story follows two small town kids, Betty Beam and Cosmo Lens as they leave Sticksville and head to Hollywood to see their names in lights. Along the way they discover where light comes from, how it behaves and how the eye works and explore how sound travels, which materials carry sound best and what makes high and low pitch.

SCIENTIFIC CONCEPTS EXPLORED

LIGHT - WHERE IT COMES FROM AND HOW IT BEHAVES

Cosmo Lens is the projectionist at the Sticksville Empire and explains to Betty Beam how it is we see things.

Initially, with the help of the audience, we work out that light comes from the sun during the day and from lights at night. We also discover that hot things give out light, like fires, candles, fireworks etc.

We move onto how we see things. Cosmo bounces a ball and explains that that is how light behaves.

Angle of bounce is the same

Light bounces off an object and into our eye so we can see it

It bounces off an object and back into our eyes so we can see it and that light bounces off at the same angle it hits an object because light travels in straight lines. The children learn this sentence. Betty and Cosmo sing a song about light and the children learn the chorus:

Light, it travels in dead straight lines.

You gotta get that right.

And just remember those dead straight lines,

Then you’ll see the light!

The audience are asked to sing the chorus again later on in the play.

In the classroom. The children could make a list of as many sources of light as they can think of, including hot things and things that give off light as a by product of their intended use.

REFLECTION OF LIGHT

Cosmo and Betty arrive at Megapics Studios where they try to get themselves a job. Cosmo is told there is a vacancy for a lighting man on the new Belisha Beacon movie and that he can have the job if he can work out how to light both sides of Belisha’s face using only the sun. With the help of the audience Cosmo and Betty work out how it can be done:

Light bounces off mirror to light

Belisha’s face

Because light travels in straight lines we see that the light can be reflected from one side of Belisha’s face to the other. Several different pieces of card are used to see which surface reflects light the best. We discover that black card reflects practically no light, that white card reflects some light but not all, we try a rough silver surface which reflects the light off in many different directions an finally we use a mirror which reflects the light from one side of Belisha’s face to the other perfectly. Thus we conclude that a mirror is the best reflector.

In the classroom: the children can do their own experiment with the reflection of light.?

Gather together several different materials and, using a piece of white card as a screen, in a darkened room with one light source(eg a torch) try using each material in turn to reflect onto the screen, like Cosmo did, to see which materials reflect well and which reflect badly. You might want to discuss why some things reflect and others do not. What is happening to the light which does not reflect

FORMATION OF SHADOWS

Cosmo tells Betty that Belisha has been acting in her own shadow and Betty asks him what he means. Cosmo explains and he and Betty play a game with the audience of guessing an object from its shadow.

Initially we introduce the idea of a material letting light pass through it and describe the object as transparent. A pane of glass is used to illustrate a material that is transparent.

Betty tries Cosmo’s sunglasses and discovers that not all light can pass through. That is because they are translucent - they are made from a material that only partially lets light through.

Finally we discover that most materials are opaque. The do not let any light through at all. Betty’s magazine is used to illustrate this type of material and we discover that if no light passes through an object what we are left with is a shadow.

	Light travels through transparent materials
	Not all light passes through translucent materials
	No light passes through opaque materials

A shadow takes on the exact shape of the object because light travels in straight lines. The light beams are not able to bend around an object so they are blocked and leave an area of dark behind the object.

In the classroom: measure your shadow at various points throughout the day, firstly when you arrive at school, then at lunchtime and then just before you go home. What has happened to your shadow and why do you think it has changed length?

A sundial works by using the shadow cast by the upright (or gnomon). It appears to change position as the sun changes position in the sky and from the position of the shadow we can tell the time of day. You can make your own sundial using a yoghurt pot and a pencil (you will need a pencil double the height of the yoghurt pot).

Place the pot upside down and push your pencil into the ground. Every hour mark where the shadow falls with the right hour so that every time the sun shines you will be able to tell the time of day from your own sundial.

REFRACTION AND HOW THE EYE WORKS

Miss Dayglo explains to Mr Megapics how it is that a movie camera works. She starts by showing him a simple experiment to illustrate refraction (however, we do not use the term.)

A pencil is put at an angle into a glass of champagne and we observe that the pencil appears to bend. We explain that this is because light travels at different speeds through transparent materials. As the light beams hit the glass and liquid they slow down, which makes them change direction.

That is why the pencil appears bent.

This knowledge is then used to explain what happens in an eye. The light bounces off an object and passes into the eye through the pupil. In a dark room we need more light and in a very light room we need less light to see so the pupil adjusts its size to let the right amount of light through. The light then hits the lens, which is made of a transparent material shaped in exactly the right way to bend the light and focus it onto the back of the eye. The light is focused and we see the image of the object on the back of the eye. (we do not deal with the image being inverted during this process)

Miss Dayglo explains that a film camera works in just the same way, letting in the right amount of light and focusing it in order to expose the image on the film at the back of the camera.

In the classroom: You can set up an experiment to see light bend. Fill a square sided bottle with water and a few drops of milk. Take two pieces of card and cut slits into them about 1mm wide. Place the cards in front of a torch on a sheet of white paper and lay the bottle in front again at an angle. Make sure the torch light shines through the slits and hits the bottle. The milk helps show how the light bends inside the bottle. Move the bottle around to see the different angles you can get from the light beam

THE FORMATION OF SOUND

Miss Dayglo explains how sound travels using an elastic band. She informs us that sound travels in waves, and uses an elastic band to demonstrate. As the band vibrates the sound waves cause the air to vibrate and the sound then vibrates the ear drum so that we can hear it. She then demonstrates that sound can travel through solids. A torch is shone at a door and Mr Megapics also shouts to Miss Dayglo. We can’t see the light but we can hear the sound of his voice. She pushes the point home by getting Mr Megapics to put his ear to a desk as she raps on it and we see that sound travels better through a solid than a gas (the air).

In the classroom: you can discuss what other materials might carry sound eg. Water carries whale and dolphin sounds over long distances, we hear water travelling through our pipes at home and if you put your ear to the ground you can hear the sound of horses hooves etc. travelling through the earth. The children can then experiment with sounds and how they travel through various materials and can make their own string-and-can telephone to see how their voices travel down the string to help them hear what each other is saying.

SOUND REDUCTION

Miss Dayglo informs Mr Megapics that although sound travels through solids it travels through some solids better than others. An experiment is set up where several different materials are used to muffle sound and we see which does the best job.

In the classroom: discuss the difference between ‘good’ sounds and those sounds that can be damaging to our ears and discuss how we can lessen the sounds: eg. Trees along motorways, closing doors, laying carpets, filling a partition wall with spongy material etc. Experiment in class with various materials to see which ones muffle sound the best and draw conclusions about them eg. Bulky, thick materials with lots of air spaces.

PITCH

Pitch is explained as how low or high a sound is. Using Van Leiderhosen’s braces we show that a loose string will give a low pitch and a taut string will give a higher pitch. We mention that vocal pitch works in the same way, with low sounds coming from looser vocal chords and higher sounds coming from tighter chords.

In the classroom; experiment with homemade musical instruments. Collect several different sizes of elastic bands and stretch them around a tin can or a shoebox. Twang the bands and see which ones give a higher pitch. Draw conclusions as to whether a band needs to be tauter or looser to give a high pitch.

AT THE END OF THE PERFORMANCE

At the end of the play there will be an opportunity for the children to ask any questions they may have about the play and the science in the play and the actors will recap the science covered in the show by quizzing the audience on the science topics covered.

Show Requirements

The actors will be arriving approximately forty minutes prior to the start time in order to set up and will need to have access to the school hall from then. They bring the set, lighting and sound equipment with them so only need access to a plug socket. They’ll need a space approximately 15’ wide by 10’ deep with the children sitting in front, either seated or on the floor. The show works well ‘on the flat’ but if it’s more convenient for the actors to use your stage, please let them know on arrival. This show lasts one hour with a two minute ‘q & a’ session at the end.